So everyone else is just wasting their time having Communion in their churches?
In the so-called "western Churches" very few intend that the sacrament involve the Real Presence of Christ. Some individual Episcopalians used to and I suspect some Lutherans did as well. But others do not intend this kind of thing. So it seems reasonable that in the normal course of events, it wouldn't happen.
GOd is merciful. So we're not going to say that the time is wasted. Pious people who are giving or hoping to give themselves to Jesus gather to commemorate the Last Supper and to meditate on and pray about all that that means, and about the unity in the Spirit they seek and all that.
I don't think God is going to say, "Tough. I never knew you. Have a nice day."
I do think, though, that maybe some aspect of the Grace of the Sacrament may be missing. Part of what we teach is not so much where God does NOT act, but rather where He has promised to act. We hold He is, as it were, guaranteed to be present in Our Eucharist, but has NOT guaranteed the same kind of graces in assemblies which do not ask for His sacramental presence. He MIGHT be there, He just didn't guarantee it.
I may be wrong on this.